Standard IC operating input levels (VIH and VIL) have been set by industry standards whether the given IC is operating with a regulated power supply with very tight tolerances or with an unregulated supply. Operating input levels for a typical DRAM for example, are set at 0.8 V.+-.100 mv for VIL and 2.4 V.+-.100 mv for VIH. Typically, DRAMs are operating from unregulated supplies that may vary from 4.5 V to 5.5 V and the input level standards must still be adhered to. There is also may instances wherein qualification of DRAMs to meet industry reliability standards requires operating the DRAM at much higher voltages than the 5.5 V specification (i.e. 7.5 V for burn-in testing of a part's mortality rate) or lower than 4.5 V (i.e. 3 V supplied ICs). In order to meet this criteria, the DRAM's input buffers must correctly accept the various signals that are used to operate a DRAM (such as the signals used to read and write data), must be able to differentiate precisely between an intended low input (determined by VIL) to that of an intended high signal (determined by VIH).